Method for updating and restoring operating software in an active region of a network element

ABSTRACT

A method for replacing a current operating software working with current files by a new operating software working with new files in a working network environment. Prior to replacement, the current operating software and current files reside in an active region of a network element, while the network element is active and maintains a prior operating software in a non-active region. The prior operating software is preserved in the non-active region and new operating software is downloaded to the non-active region and installed there while the current files are saved and updated to create updated files conforming to the new operating software. The network element is then rebooted such that the active region and the non-active region are swapped, thus replacing the current operating software working with the current files with the new operating software working with the updated files. The prior operating software preserved in the non-active region is then reinstalled and a redistribution of the current files to the active region and prior files to the non-active region is performed. The method can be applied to network elements equipped with a processing element module (PEM) and a persistent storage module (PSM) where the active region is partitioned or distributed between the PEM and PSM and the non-active region is also partitioned or distributed between the PEM and PSM.

FIELD OF THE INVENTION

[0001] The present invention relates generally to replacing or updatingof operating software in an active region of a network element while thenetwork element is active, as well as restoring the operating softwaresuch as in case of update malfunction.

BACKGROUND

[0002] As computer networks grow and expand it is important that allelements of the network operate in a coordinated fashion. One of theimportant steps in this process is to ensure that software on thevarious network elements is operated and updated in a coordinatedmanner. The problem of updating pre-existing, region-dependent softwarewithout affecting the region-dependent nature of the software andtransporting the updated software to the destination (e.g., via theinternet), extracting, loading and merging the updated software has beenrecognized, for example, by Randall in U.S. Pat. No. 5,978,916. Thispatent teaches a method, system and computer program for updatingsoftware with a common update module.

[0003] Certain networks require more than a coordinated software update.For example, communications networks have to operate with minimaldowntime for administration and maintenance. When system files oroperating software is being updated, the network element has to maintainfull capability of transporting communication traffic and ensure minimuminterruption in administration and maintenance capability. This is adifficult task, since operating software consists of files that arewrite-protected or access-locked to avoid accidental overwriting duringroutine operation.

[0004] In U.S. Pat. Nos. 6,199,203; 6,154,878 and 6,202,205 Saboff etal. teach memory management techniques for on-line replaceable software,e.g., a software library, such that the state of the software componentis preserved after an update to the software component. This isaccomplished by allocating two types of memory: transient memory andenduring memory (to be preserved between two calls of the library). Inthis method, when new version of the software is updated software fromthe transient memory is released, while the enduring memory is preservedfor use by new software versions. In U.S. Pat. No. 5,764,989 Gustafssonet al. teach an interactive program or software development system whichobviates the need to halt execution of a program under development orduring a maintenance update to correct programming errors.Unfortunately, Saboff's technique is limited to the patching of memoryand it cannot be applied to upgrade operating software in acommunications network and Gustafsson's teaching cannot be extended toupdates of operating systems with the above-mentioned interruptionrequirements in communications networks.

[0005] In fact, updating of system software in a network challenges themanagement of operating systems as well as operational continuity,memory management and data recovery. In U.S. Pat. No. 5,715,462 Iwamotoet al. present an updating and restoration method of system file that isdesigned for operating system (OS) updates and takes advantage ofstoring the same OS in separate memory areas. The executing OS in thefirst memory area is terminated and the OS in the second area isinitiated. After the system files stored in the first area are releasedfrom access lock, substitute files provided in advance by using a filereplacing function of the second OS replace them. When such as filereplacement fails for some reason, the original operating system filesare immediately restored.

[0006] Iwamoto's teaching moves a long way to solving the problem ofupgrading or updating of operating system software and can be applied incommunication networks. It offers safety in that it preserves files toprovide for recovery and reinitiating of old operating software in caseof failure. Unfortunately, Iwamoto's approach has several drawbacks.First, there is a lengthy period of loss of visibility to a networkmanager. This is the time involved in performing two terminations andactivations or two reboot operations and new software installation. In asuccess scenario this time can be about 15 minutes, and close to onehour in a worst-case failure scenario. Second, this update method haspoor failure handling capability with respect to detecting the conditionof the system and reporting alarms. Since the application softwarecannot be started during the procedure, it is not possible to use thealarm mechanisms provided by the application software. Third,implementation and testing are complicated in this approach. Thecombinations of failure cases during the reboots can be dramatic andcause enormous increases in implementation and testing time.

[0007] Therefore, the problem of rapid, simple and effective operatingsystem updates in networks with minimal loss of visibility to a networkmanager remains unsolved. This problem is especially acute incommunications networks that have to maintain high visibility anderror-free operation.

OBJECTS AND ADVANTAGES

[0008] In view of the above, it is an object of the present invention toprovide a method for updating or replacing a current operating softwareand current files with new operating software and new files in anefficient, simple and rapid manner. Specifically, it is envisioned thatthe method provide for replacing the operating software and files withminimum loss of visibility to the network manager.

[0009] It is another object of the invention to ensure that the methodfor updating the system software sustains minimal loss of visibilityeven in case of worst-case failure scenarios.

[0010] It is yet another object of the invention to ensure that theimplementation of the update method reduces failure cases during rebootsby minimizing the number of reboots that need to be performed.

[0011] These and other objects and advantages will become apparent uponreading the detailed description.

SUMMARY OF THE INVENTION

[0012] The objects and advantages of the invention are achieved by amethod for replacing a current operating software working with currentfiles by a new operating software working with new files. Prior toreplacement, the current operating software and current files reside inan active region of a network element, while the network element isactive and maintains a prior operating software in a non-active region.In accordance with the method, the prior operating software is preservedin the non-active region and new operating software is downloaded to thenon-active region. The new operating software is installed in thenon-active region and the current files are saved. The current files areupdated to create updated files conforming to the new operatingsoftware. The network element is then rebooted such that the activeregion and the non-active region are swapped, thereby replacing thecurrent operating software working with the current files with the newoperating software working with the updated files.

[0013] The method further includes the step of reinstalling in thenon-active region the prior operating software that was preserved in thenon-active region. A redistribution of the current files to the activeregion and prior files to the non-active region is also performed.

[0014] In a preferred embodiment the network element has a processingelement module (PEM) and a persistent storage module (PSM) and theactive region is partitioned or distributed between the PEM and PSM. Thenon-active region is also partitioned or distributed between the PEM andPSM. In this embodiment, the current files are saved in the activeregion of the PSM and in the active region of the PEM. Furthermore, whendownloading the new operating software it is convenient to download loadfiles of the new operating software into the non-active region of thePSM and PEM.

[0015] The prior operating software has prior files, which typicallyinclude a database. The step of preserving the prior operating softwareincludes storing the load files of the prior operating software in thenon-active region in the PSM. The prior files are also preserved in thenon-active region in the PEM and PSM. The prior operating software iserased during installation of the new OS files.

[0016] Because of space, it is also preferable to download the newoperating software by downloading load files of the new operatingsoftware into the non-active regions defined in the PSM. Installation ofthe new operating software is then accomplished through extracting andinstalling the load files to build the new operating software. The newoperating software is installed in the non-active region of the PSM andPEM.

[0017] In one embodiment, the current files are stored in the activeregion. For example, the current files can be stored in the activeregion of the PSM and PEM. Thus, after the reboot, these files will belocated in the non-active region of the PSM and PEM. These current filestypically include a database.

[0018] The method of the invention can be used to upgrade or updateoperating systems in network elements belonging, e.g., to acommunication network. In one embodiment, the new operating software isa software release of the current operating software. Of course, the newoperating software can also be a maintenance version or any othermodified version of the current operating software.

[0019] When the new operating system malfunctions or if the networkadministrator wishes to revert to the current operating software for anyreason, the current operating software can be restored. The step ofrestoring involves rebooting the network element such that the activeregion and non-active region are swapped again, provided the swap rebootwas successful. This replaces the new operating software working withupdated files by the current operating software working with the currentfiles.

[0020] The invention also includes a storage medium that performs theabove-enumerated steps of replacing the current operating softwareworking with current files by the new operating software working withupdated files. Specifics and details about the method of invention andthe steps stored in the storage medium are found in the followingdetailed description with reference to the attached drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021]FIG. 1 is a schematic diagram of a communication network in whichthe method of the invention is applied.

[0022] FIGS. 2A-I are diagrams illustrating the steps of the method.

DETAILED DESCRIPTION

[0023] The method of invention will be best understood by firstexamining a communication network 10 of FIG. 1, in which the method isapplied. It will be clear to a person skilled in the art thatcommunication network 10 is an exemplary network, e.g., the internet,and that other networks and computer systems exhibiting differentnetwork architectures can take advantage of the method.

[0024] Communication network 10 has a host computer 12 and a file server14. Host computer 12 is, for example, a data base machine thatsupervises the operation of network 10. Thus, host computer 12 overseesthe transmission and reception of data 20 within network 10. Hostcomputer 12 also manages file server 14 to which files can be stored andfrom which files, such as files 16, may be sent to any given networkelement, such as network element 18, belonging to network 10.

[0025] Network 10 has various resources including data transmissionlines (e.g., optical fibers), repeater stations, routers, filters andthe like. These resources transmit and distribute data 20 throughoutnetwork 10 and are generally indicated by reference 22. A person skilledin the art will appreciate that any specific type of network will beprovisioned with appropriate resources 22.

[0026] Network element 18 is connected to network 10 such that it cansend and receive data 20. Network element 18 includes a number ofcircuits, data processing devices and modules 24. The modules include aprocessing element module (PEM) 26 and a persistent storage module (PSM)28. PEM 26 has a central processing unit 30, a first storage unit 32 anda second storage unit 38. In this embodiment both storage units 32, 38are hard disk drives, but a person skilled in the art will recognizethat any other suitable storage units affording sufficiently rapidaccess times for processing functions which PEM 26 is to perform inmanaging the communications of network element 18 can be employed. PSM28 is equipped with its own central processing unit 34 and its ownstorage units 36, 40 which are also hard disk drives in this embodiment.PSM 28 is designed to provide redundant storage to PEM 26, in case offailure.

[0027] Hard drive 32 is selected as the active drive of PEM 26 and harddrive 38 as the non-active drive. In PSM 28 hard drive 36 is chosen asthe active drive and hard drive 40 as the non-active drive. An activeregion 42 is defined on drives 32, 36 in PEM 26 and PSM 28. A non-activeregion 44 is defined on drives 38, 40 in PEM 26 and PSM 28. Active andpassive regions 42, 44 are thus partitioned or distributed among harddrives 32, 36 and 38, 40 and the division between passive and activeregions 42, 44 is indicated by a dashed line. The software and files inactive region 42 are access-locked or write-protected to preventaccidental overwriting during routine operation of network element 18.

[0028] An external network manager 46 has access to network element 18via interface 48. External network manager 46 monitors the operation ofnetwork element 18 and requires that the operations being performed bynetwork element 18 be visible. Network manager 46 requires maximumvisibility, preferably at all times, of the operation being performed bynetwork element 18 to ensure that administrative and maintenancefunctions can be performed.

[0029] Active region 42 in PEM 26 and PSM 28 is synchronized byappropriately controlling drives 32, 36 as indicated by arrows S. Suchsynchronization is well understood by those skilled in the art.Meanwhile, non-active region 44 in PEM 26 and PSM 28 is notsynchronized. Non-active region 44 in PEM 26 and PSM 28 is notwrite-protected and serves to store files. In fact, active region 42 inPEM 26 stores a current operating software (OS) 50 and current files 52.OS 50 works with current files 52, which typically include a database,to coordinate the operation of network element 18. A copy of current OS50′ and of current files 52′ is also installed and maintained in synchin active region 42 of PSM 28. Non-active region 44 on both PEM 26 andPSM 28 contains a prior OS 54, 54′ and prior files 56, 56′ respectively.Additional files can also be stored in non-active region 44, especiallyin PSM 28. For that reason, it is preferable that the capacity of harddrive 40 be large enough to accommodate numerous software files over andabove prior OS 54′ and prior files 56′.

[0030] Modules 24 also include transport cards, of which only two cards72, 74 are shown for simplicity. Transport cards 72, 74 are typicallycircuit packs placed on the shelves of network element 18 alongside PEM26 and PSM 28, but in different slots. Cards 72, 74 perform all datatraffic processing functions, including amplifying,multiplexing/demultiplexing, wavelength conversion and other functionsrequired to process and route data 20. To perform these functions,transport cards 72, 74 run corresponding applications. Thus, whenactive, transport cards 72, 74 carry a software load including anapplication, a boot loader, a microboot loader and any other necessarysoftware (e.g., field-programmable gate array (FPGA) assignments), as isknown to those skilled in the art. Preferably, the software on transportcards 72, 74 is stored in an active flash memory region 76 and anon-active flash memory region 78 on each transport card 72, 74. Boththe active and non-active regions carry the exact same software loadsfor redundancy.

[0031] During normal operation current OS 50 in conjunction with currentfiles 52 operates network element 18 and uses non-active region 44 ondrives 38, 40 for backing up and storing files. Synchronized current OS50′ and current files 52′ also in active region 42 can be used torecover PEM 26 after a failure, e.g., in case of drive 32 malfunction.It should be noted that in a typical network element 18, PSM 28 cannotuse current OS 50′ and current files 52′ to operate network element 18in case of failure of PEM 26.

[0032] If it is desired that network element 18 operate with prior OS54, a reboot procedure is performed. During reboot OS 54, 54′ with files56, 56′ are re-activated by swapping active region 42 and passive region44. Rebooting drives 32, 36, 38, and 40 in accordance with standardprocedures is known in the art. The actual flow of data 20 is processedand routed by transport cards 72, 74 under the direction of softwareexecuting from active region 76 of their flash memories. In case offailure or malfunction of transport cards 72, 74 the software innon-active flash memory region 78 is activated and used to direct thetraffic of data 20.

[0033] Periodically, a new release, maintenance update or otherwise new,patched, modified or upgraded OS is to be installed on network element18. Such new OS can be distributed from file server 14 on instructionsfrom host computer 12 and delivered in the form of load files 16 tonetwork element 18. Alternatively, the new OS can be provided throughnetwork administrator 46 or by otherwise loading new OS via a localinterface from an external device, e.g., an external removable diskdrive.

[0034] It is important that the replacement of current OS 50, 50′working with current files 52, 52′ by new OS working with new files beperformed in a manner which minimizes loss of visibility to networkmanager 46, minimizes probability of malfunctions and uses the leastreboot operations possible. The present method provides for suchreplacement, as will now be explained in reference to FIGS. 2A-I.

[0035]FIG. 2A illustrates the condition of active region 42 andnon-active region 44 on PEM 26 and PSM 28 prior to any updatingactivity. During this time, network manager 46 is able to monitor andmaintain the operation of network element 18. Current OS 50, in thepresent embodiment OS version X.1.0, and current files 52 installed inactive region 42 of PEM 26 are controlling the operation of networkelement 18. Since OS X.1.0 50 and current files 52 on PEM 26 aresynchronized with OS X.1.0 50′ and current files 52′ on PSM 28, OS X.1.050′ and current files 52′ can be used to recover PEM 26 in case of amalfunction.

[0036] Non-active region 44 on both PEM 26 and PSM 28 contains prior OS54, 54′, in this case X.0 and prior files 56, 56′ respectively. Thus, itis also possible to reboot PEM 26 and PSM 28 such that prior OS 54, 54′and prior files 56, 56′ are in active region 42 and current OS 50, 50′along with current files 52, 52′ are in non-active region 44. Thisprocess can be used to revert to prior OS 54, 54′ for any desiredreason. The process involves rebooting PEM 26 and PSM 28 and placingdrives 38 and 40 in active region 42 while assigning drives 32, 36 tonon-active region 44 (see FIG. 1).

[0037] The state illustrated by FIG. 2A with current OS X.1.0 50, 50′and prior OS X.0 54, 54′ stored in active and non-active regions 42, 44of PEM 26 and PSM 28 is frequently referred to as the activated state.The rebooting procedure is also referred to as a swap reboot and isfamiliar to those skilled in the art.

[0038]FIG. 2B illustrates the first step taken in replacing current OSX.1.0 50, 50′ working with current files 52, 52′ by new OS and new fileswhen network element 18 is in the activated state shown in FIG. 2A.Specifically, before the replacement, prior OS X.0 54, 54′ and priorfiles 56, 56′ are preserved in non-active region 44. Preferably, thepreservation involves saving load files 62 of prior OS X.0 54 and ofprior files 56 where sufficient storage space is available.Conveniently, this space is provided in non-active region 44 of PSM 28.Prior OS X.0 54 will be erased after load files 62 of prior OS X.0 54are stored and during installation of new OS files.

[0039]FIG. 2C illustrates the next step, during which load files 64 ofnew OS X.1.1 66 are downloaded to non-active region 44 of PEM 26 and PSM28. Alternatively, load files 64 can be downloaded only to non-activeregion 44 of PSM 28 and from there be installed in non-active region 44of PEM 26. This approach is preferable, as it conserves disk space.

[0040] Load files 64 can be delivered through network 22, i.e., they canbe embedded in files 16 sent from file server 14 upon authorization ofhost computer 12. Alternatively, load files 64 can be supplied locally.For example, network element 18 may be equipped with a drive for readingremovable media such as a CD drive (not shown) and load files 64 can beprovided on a readable storage medium such as a CD. In still anotherapproach, a personal computer (PC) can be connected to network element18 via a craft interface port to download load files 64. A personskilled in the art will recognize that there are numerous ways in whichload files 64 can be delivered to network element 18.

[0041] New OS X.1.1 66 is installed in non-active region 44 of PEM 26.In addition, a redundant copy of new OS X.1.1 66′ is installed innon-active region 44 of PSM 28. The installation involves extractingload files 64 installing the extracted files and building new OS X.1.166 and new files 68 on PEM 26 and respective copies of OS X.1.1 and ofnew files 66′, 68′ on PSM 28. During this process prior OS X.0 54, 54′and prior files 56, 56′ are overwritten. In other words, prior OS X.054, 54′ as well as prior files 56, 56′ are erased when new OS X.1.1 66,66′ and new files 68, 68′ are installed. It should be noted thatthroughout this process the operation of network element 18 is visibleto network manager 46.

[0042] In the next step shown in FIG. 2D new files 68, 68′ are updatedwith the information being used by current files 52, 52′.

[0043] Current files 52, 52′ typically contain a database and otherfiles that are formatted to cooperate with current OS X.1.0 50, 50′. Itis important that the contents of this database and of the other filesbe transmitted to new files 68, 68′ so that new OS X.1.1 66 can pick upthe work seamlessly from current OS X.1.0 50. This can be done in anysuitable manner known to those skilled in the art. For example, the datafrom the database and any other files belonging to current files 52, 52′can be imported into new files 68, 68′ directly. Alternatively, thedatabase and files can be converted or reformatted to conform to thestandards of files 68, 68′ and merged. In any case, this step should beperformed just prior to the subsequent steps to ensure that new OS 66,66′ can start operating with new files 68, 68′ containing up-to-dateinformation.

[0044] In the subsequent step, illustrated in FIG. 2E copies of currentfiles 52, 52′ are saved as backup files 70, 70′ on PEM 26 and PSM 28respectively. Backup files 70, 70′ are kept in active region 42 of PEM26 and PSM 28. It should be noted that up until the step of FIG. 2E,network manager 46 can monitor the activity of PEM 26 and PSM 28.

[0045] During the next step, network element 18 is rebooted. Thisprocedure is illustrated in FIG. 2F and it involves restarting both PEM26 and PSM 28 and re-assigning drives 32, 36, 38, and 40. During therestarting procedure active and non-active regions 42, 44 areredistributed or repartitioned. In particular, drives 32, 36 aredesignated as non-active while drives 38, 40 are selected as active.Thus, the rebooting operation swaps the active and non-active regions42, 44. Formerly non-active region 44 of PEM 26 and PSM 28 is now activeregion 42′ while formerly active region 42 of PEM 26 and PSM 28 becomesnon-active region 44′. The appropriate rebooting procedures are wellknown to those skilled in the art.

[0046] As a result of the reboot, current OS X.1.0 50, 50′ working withcurrent files 52, 52′ are in non-active region 44′. Meanwhile, new OSX.1.1 66, 66′ working with new files 68, 68′ are in active region 42′.Thus, the reboot replaces current OS X.1.0 with new OS X.1.1 in activeregion 42′. Meanwhile, backup files 70, 70′ of current files 52, 52′ arein non-active region 44 of PEM 26 and PSM 28 respectively. During therebooting operation network element 18 is not visible to network manager46.

[0047] After the reboot new OS X.1.1 66, 66′ and new files 68, 68′ areplaced into operation and synchronized, as shown in FIG. 2G. At thistime network element 18 starts running under the direction of new OSX.1.1 and communication with network element 18 is re-established. Atthis point, active region 42′ is fully functional and network manager 46can once again monitor the activity of network element 18. In otherwords, visibility of network element 18 is restored at this time.

[0048] To complete the process backup files 70, 70′ and load files 62stored in active and non-active regions 42′, 44′ are redistributed. Inparticular, backup files 70, 70′ are moved to active region 42′ on PEM26 and PSM 28 respectively.

[0049] Additionally, load files 62 of prior OS X.0 54, 54′ and priorfiles 56, 56′ are moved to non-active region 44′ on PSM 28.

[0050]FIG. 2H illustrates a clean-up step performed after successfulinstallation of new OS X.1.1 66, 66′ and new files 68, 68′. The clean upinvolves removing current OS X.1.0 50, 50′ and current files 52, 52′from non-active region 44′. This is done by overwriting prior OS X.0 54,54′ and prior files 56, 56′ in non-active region 44′ on PEM 26 and PSM28 respectively. This is done in cases where network manager 46 wishesthat upon reboot prior OS X.0 54, 54′ rather than current OS X.1.0 50,50′ operate network element 18.

[0051] If sufficient space is available, current OS X.1.0 50, 50′ or itsload files can be stored for eventual future use. Also, back-up files 70of current files 52, 52′ containing the database can be stored to asuitable storage device (not shown) in network element 18.

[0052]FIG. 2I illustrates the result of the process. Network element 18is once again in the activated state and is committed to operating withnew OS X.1.1 66, 66′ and new files 68, 68′.

[0053] It should be noted that new OS X.1.1 66, 66′ and new files 68,68′ can be aborted upon instructions from network manager 46. In thiscase, prior software 54, 54′ and prior files 56, 56′ are re-activated byanother reboot and swap of the active and non-active regions 42′, 44′ torevert to the previous configuration.

[0054] The method of the invention can be used to upgrade or update OSsoftware and files in network elements belonging to a communicationnetwork and operating on live data or in other networks. The methodlimits the loss of visibility of network element 18 because only onereboot is necessary to switch network element 18 to the new OS, afterwhich network element 18 continues working seamlessly with actual data.During other stages of the OS replacement, even in case of most of thefailure recovery scenarios, network manager 46 has visibility of theoperations being executed on network element 18.

[0055] Implementation and testing is straightforward because the failurepath in failed upgrades is conceptually, the exact reverse of thesuccess path. Furthermore, failures in any recovery activities performedin the non-active region will not cause the entire method to fail. Thisis because OS in the current region is already updated successfully andrunning when the final operations in the non-active regions are beingperformed. In fact, the problems in the non-active region can besupplied with appropriate alarms and fixed during separate steps. Suchalarms and steps are well known to those skilled in the art.

[0056] The method of invention can be used in any networks. It fact, itis advantageous to also use this method for updating a current card OSwith a new card OS in transport cards 72, 74 of network element 18.Preferably, at this time, new OS X.1.1 66, 66′ and new files 68, 68′ arealready downloaded and installed in non-active region 44 of PEM 26 andPSM 28.

[0057] The process of updating transport cards 72, 74 is performed byfollowing the steps shown in FIGS. 2A-E and operating on active andnon-active flash memory regions 76, 78. Thus new card OS andaccompanying new card files which are to replace current card OS andcurrent card files are loaded. After PEM 26 and PSM 28 are successfullyrebooted and active and non-active regions 42, 44 are swapped to activeand non-active regions 42′, 44′ the update of transport cards 72, 74 isresumed by following the steps illustrated in FIGS. 2F-I. During thesesteps, non-active flash memory region 78 becomes the active flash memoryregion and is committed with new card OS and new card files. Failure indelivering new OS or files, or failure in completing restart during thereboot and swap of active and non-active flash memory regions 76, 78 isconsidered as failure of the entire process. In other words, the upgradeof network element 18 is considered a failure and reboot to revert backto current OS and current files is performed on PEM 26, PSM 28 as wellas on transport cards 72, 74.

[0058] The method of invention can be used in many types of networks andat various levels. As illustrated in the above embodiment, the methodcan even be performed to update various components of the same network.In another embodiment, the steps of the method are stored in a storagemedium. The method can thus be loaded into any suitable processor on anetwork requiring OS replacement and executed. A person skilled in theart will recognize that many extensions and alternative embodiments ofthe invention are possible and that the full breadth of the invention ishence defined by the scope of the appended claims and their legalequivalents.

We claim:
 1. A method for replacing a current operating software workingwith current files, said current operating software and said currentfiles residing in an active region of a network element while saidnetwork element is active and maintains a prior operating software in anon-active region, said method comprising: a) preserving said prioroperating software in said non-active region; b) downloading a newoperating software to said non-active region; c) installing said newoperating software in said non-active region; d) saving said currentfiles; e) updating said current files to create updated files conformingwith said new operating software; and f) rebooting said network elementsuch that said active region and said non-active region are swapped,thereby replacing said current operating software working with saidcurrent files with said new operating software working with said updatedfiles.
 2. The method of claim 1, further comprising reinstalling in saidnon-active region after rebooting said prior operating softwarepreserved in said non-active region.
 3. The method of claim 1, furthercomprising redistributing said current files to said active region andsaid prior files to said non-active region.
 4. The method of claim 1,wherein said network element comprises a processing element module and apersistent storage module, and said method further comprisesdistributing said active region among said processing element module andsaid persistent storage module.
 5. The method of claim 4, furthercomprising distributing said non-active region among said processingelement module and said persistent storage module.
 6. The method ofclaim 5, wherein said step of saving comprises saving said current filesin said active region defined in said persistent storage module.
 7. Themethod of claim 6, wherein said step of saving further comprises savingsaid current files in said active region defined in said processingelement module.
 8. The method of claim 5, wherein said step ofdownloading comprises downloading load files of said new operatingsoftware into said non-active region defined in said persistent storagemodule and in said processing element module.
 9. The method of claim 5,wherein prior operating software has prior files and said step ofpreserving said prior operating software comprises storing load files ofsaid prior operating software in said non-active region defined in saidpersistent storage module.
 10. The method of claim 9, further comprisingpreserving said prior files in said non-active region defined in saidpersistent storage module.
 11. The method of claim 9, further comprisingerasing said prior operating software.
 12. The method of claim 5,wherein said step of downloading said new operating software comprisesdownloading load files of said new operating software into saidnon-active region defined in said persistent storage module.
 13. Themethod of claim 5, wherein said step of installing said new operatingsoftware comprises installing said new operating software in saidnon-active region defined in said persistent storage module and in saidprocessing element module.
 14. The method of claim 1, wherein said stepof saving said current files comprises saving said current files in saidactive region.
 15. The method of claim 1, wherein said current filescomprise a database.
 16. The method of claim 1, wherein said step ofdownloading comprises downloading load files of said new operatingsoftware and extracting said load files to build said new operatingsoftware.
 17. The method of claim 1, wherein said new operating softwarecomprises a software release of said current operating software.
 18. Themethod of claim 1, wherein preserving said prior operating softwarecomprises storing load files of said prior operating software.
 19. Themethod of claim 1, further comprising restoring said current operatingsoftware.
 20. The method of claim 19, wherein said step of restoringcomprises rebooting said network element such that said active regionand said non-active region are swapped, thereby replacing said newoperating software working with said updated files with said currentsoftware working with said current files.
 21. The method of claim 19,wherein said step of restoring is performed upon a malfunction.
 22. Themethod of claim 1, wherein said network element further comprisestransport cards having an active flash memory region and a non-activeflash memory region, and a swap reboot is performed in said active flashmemory region and said non-active flash memory region to replace acurrent card operating software with a new card operating software. 23.A storage medium tangibly embodying the steps for replacing a currentoperating software working with current files, said current operatingsoftware and said current files residing in an active region of anetwork element while said network element is active and maintains aprior operating software in a non-active region, said steps comprising:a) preserving said prior operating software in said non-active region;b) downloading a new operating software to said non-active region; c)installing said new operating software in said non-active region; d)saving said current files; e) updating said current files to createupdated files conforming with said new operating software; and f)rebooting said network element such that said active region and saidnon-active region are swapped, thereby replacing said current operatingsoftware working with said current files with said new operatingsoftware working with said updated files.